This book is already getting noticed. In ''The Intimate World of Abraham Lincoln,'' C. A. Tripp contends that Lincoln had erotic attractions and attachments to men throughout his life, from his youth to his presidency. He further argues that Lincoln's relationships with women were either invented by biographers (his love of Ann Rutledge) or were desolate botches (his courtship of Mary Owens and his marriage to Mary Todd). Tripp is not the first to argue that Lincoln was homosexual -- earlier writers have parsed his friendship with Joshua Speed, the young store owner he lived with after moving to Springfield, Ill. -- but he assembles a mass of evidence and tries to make sense of it.

Tripp died in May 2003, after finishing the manuscript of this book, which means he never had a chance to fix its flaws. The prose is both jumpy and lifeless, like a body receiving electric shocks. Tripp alternates shrewd guesses and modest judgments with bluster and fantasy. He drags in references to Alfred Kinsey (with whom he once worked) to give his arguments a (spurious) scientific sheen. And he has an ax to grind. He is, most famously, the author of ''The Homosexual Matrix.'' Published in 1975, it was a document of gay liberation. Since the other president sometimes thought to have been gay is the wretched James Buchanan, what gay activist wouldn't want to trade up to Lincoln? Still, obsession can discover things that have been overlooked by less fevered minds.

Tripp surveys seven of Lincoln's relationships, four with men and three with women, as well as two episodes from his early life. The discussion of Lincoln's youth is worthless. Relying on Lincoln's law partner and earliest biographer, William Herndon, Tripp decides that Lincoln reached puberty when he was 9 years old. Since Kinsey concluded that early maturing boys tended to become witty masturbators with lots of homosexual experience, Tripp concludes the same of Lincoln. He claims even more for Lincoln's adolescence, including a source for his religious heterodoxy. ''Since Lincoln had already arrived on his own at the powerful pleasures of orgasm . . . one can be sure that like most precocious youngsters he was in no mood to give it all up for bookish or Bible reasons.'' One can be sure, if one is as credulous as Tripp.

Lincoln's story becomes interesting when Tripp discusses real people. In 1831, when he was 22, Lincoln moved to New Salem, an Illinois frontier town, where he met Billy Greene. Greene coached Lincoln in grammar and shared a narrow bed with him. ''When one turned over the other had to do likewise,'' Greene told Herndon. Bed-sharing was common enough in raw settlements, but Greene also had vivid memories of Lincoln's physique: ''His thighs were as perfect as a human being could be.'' Everyone saw that Lincoln was tall and strong, but this seems rather gushing.

Six years later, Lincoln moved to Springfield, where he met Joshua Speed, who became a close friend; John G. Nicolay and John Hay, two early biographers, called him ''the only -- as he was certainly the last -- intimate friend that Lincoln ever had.'' Lincoln and Speed shared a double bed in Speed's store for four years (for two of those years, two other young men shared the room, though not the bed). More important than the sleeping arrangements was the tone of their friendship. Lincoln's letters to Speed before and after Speed's wedding in 1842 are as fretful as those of a general before a dubious engagement. Several of them are signed ''Yours forever.''

By contrast, Lincoln's relations with women are either problematic or distant. Ann Rutledge was the daughter of a New Salem tavernkeeper with whom Lincoln boarded in 1832. Three years later she died of malaria and typhoid. Lincoln biographers have been feuding for decades over whether Lincoln loved her. Tripp, naturally, sides with the skeptics. He concedes that Lincoln was devastated by her death, but argues that it was death itself that distressed him.